In recent years, a card-type memory device, such as an IC card, has been put into practical use. Some IC cards comprise a detachable card-type module which contains a memory. FIG. 4 shows an example of the card-type module commonly used in portable computers. FIGS. 5(a), 5(b) and 6 show a semiconductor module used for the card-type module. In particular, FIG. 5(a) is a perspective view of a surface of the semiconductor module which is sealed by resin. FIG. 5(b) is a perspective view of the bottom surface of the semiconductor module on which terminals connected to the external circuit are provided. FIG. 6 is a cross-sectional view of the semiconductor module. In the semiconductor module shown in FIG. 6, a semiconductor chip 25 is bonded on the surface of a substrate 13, and a bonding pad 29 of the semiconductor chip 25 is connected by a gold wire 27 to a terminal formed on the substrate 13 to be connected to the semiconductor chip. The semiconductor chip may be connected to the chip connecting terminal on the substrate by a flip-chip bonding technique using a bump. The semiconductor chip 25 is then sealed by a molding portion 14. Typically, a non-volatile semiconductor memory, such as a flash EEPROM, is used as the semiconductor chip 25. The periphery of the substrate 13 is exposed to the outside and surrounds the resin mold section 14. The opposite surface of the substrate is provided with a plain connection terminal 12 which can be connected to external circuits. Commonly, the external connection terminal 12 is connected to the chip connecting terminal 26 by a through hole 28.
Referring to FIG. 4, a semiconductor module 10 formed in the above-mentioned manner is bonded to a concave portion 11a of a module supporter 11 made of resin or plastic, so that the semiconductor module 10 is embedded in the concave portion 11a. The external connection terminals 12 are exposed to the outer environment on substantially the same plain as that of the module supporter 11. The periphery portion of the substrate 13 is bonded to the concave portion 11a of the module supporter 11, preferably, with the use of liquid or sheet-like adhesive.
FIGS. 7(a)-7(c) show one method of bonding a semiconductor module and a module supporter with the sheet-like adhesive piece. As shown in FIG. 7 (a), a semiconductor module 17 is cut away from a substrate 15 which has a plurality of serially arranged semiconductor modules. In particular, a resin mold section 16 corresponding to each semiconductor module 17 is serially arranged on the substrate 15. Next, adhesive pieces 19, each having a shape corresponding to a bonding interface of a semiconductor module and a module supporter, are cut away from an adhesive sheet 18, as shown in FIG. 7(b). Each adhesive piece has a shape of a frame. The adhesive sheet 18 and the adhesive pieces 19 have adhesive materials on both sides. Each adhesive piece 19 is then applied to the concave portion 11a of the module supporter 11, as shown in FIG. 7(c). Finally, as shown in FIG. 7(c), the semiconductor module 17 is placed substantially on top of the adhesive piece 19 for bonding to the module supporter 11.
FIG. 8 shows an alternative method for bonding a semiconductor module and a module supporter with the sheet-like adhesive pieces. As shown in FIG. 8(a), a semiconductor module 17 is cut away from a substrate 15 which has a plurality of serially arranged semiconductor modules. Next, adhesive pieces 19 each having the same area as that of one semiconductor module are cut away from an adhesive sheet 18, as shown in FIG. 8(b). Subsequently, each of the adhesive pieces 19 is applied to the semiconductor module 17, as shown in FIG. 8(c). The semiconductor module 17 is then placed substantially on top of the concave portion 11a of the module supporter 11, such that the semiconductor module 17 applied with the adhesive pieces 19 is bonded to the concave portion 11a of the module supporter 11, as shown in FIG. 8(d).
Alternatively, when a liquid adhesive is used to bond the semiconductor module 17 with the module supporter 11, a semiconductor module 17 is cut away from a plurality of semiconductor modules formed on a substrate 15. Then, the liquid adhesive is applied to the portion of the module supporter, on which the semiconductor module is to be bonded.
In the conventional process described above, it is difficult to cut away from the adhesive sheet the adhesive pieces each having the shape of the bonding portion of the module supporter 11 for bonding the semiconductor module and the module supporter. To cut the adhesive pieces having the corresponding shape of the bonding portion with a die, the adhesive sheet must be divided into three portions (i.e., outer portion, frame portion, and inner portion), and thus a special die is required. Further, the cutting edge of the die become dull after continuous use so that the adhesive material from the adhesive sheet smears over the die.
In addition, the adhesive piece cut in the shape of the bonding portion of the module supporter 11 is very thin, small, sticky and light. As a result, handling of the adhesive piece can be problematic. In particular, if the user wishes to perform the bonding process automatically, it may be impossible for a machine to deal with such an adhesive piece with ease.
It is also difficult to precisely align the adhesive pieces with the bonding portion of the module supporter 11. In particular, if the adhesive piece is misaligned, the adhesive piece may undesirably protrude beyond the bonding surface and encroach on the external connection terminals. This misalignment results in a undesirable appearance and increases the defect rate in the final products.
To prevent such misalignment of the adhesive piece to the bonding surface, an adhesive piece having a smaller adhesive area than that of the bonding portion might be used. However, a small adhesive piece does not have strong adhesion.